Bemused by results!

[Judthepud]

Hi, I increased my Levothyroxine a month ago from 150mcg three times a week/125mcg four times a week to 150mcg five times a week/125mcg twice a week. Results as follows:

Lower dose: TSH 1.3 (0.27-4.20); Free Thyroxine 17.100 (12.00-22.00); Free T3 4.94 (3.10-6.80)

Higher dose: TSH 0.899 (0.27-4.20); Free Thyroxine 16.200 (12.00-22.00); Free T3 4.49 (3,10-6.80)

Why have my FT4 and FT3 gone down in the past month while on a slightly higher dose?

My history is that I increased my dose from 125mcg to 150mcg at the end of last year and a couple of months later started having anxiety/panic attacks. I assumed I was over-medicated and reduced back down (but no blood results to confirm over-medication). Then Medichecks bloods showed that I had become hypothyroid on the lower dose and I've been gradually increasing my dose ever since, although the anxiety is still around (which may be unrelated). Other blood results (vitamins and minerals) have been fine. Are my most recent results OK? Should I leave well alone, or should I increase to 150mcg daily?

Would be really grateful for advice and any thoughts on why my thyroid hormones are now lower than before despite being on a higher dose?

Thanks.

[jimh111]

This is a tiny change in dose. Your hormone levels vary from day to day more than this. Hence not worth running a blood test with such a small change.

[Judthepud in reply to jimh111]

Do I take the risk of increasing back to 150mcg daily despite my concerns that I may have been over-medicated on that dose? Or do you think my blood results are fine as they are? Someone said I should be aiming for my FT3 and FT4 to be in the upper 70-75% of the range, but if I increase my dose much more might I become hyper? Also, if day-to-day hormone levels vary, then my hormones might sometimes already be in the upper part of the range. Let me know if you have any advice to offer.

Thank you so much for taking the time to respond.

[jimh111 in reply to Judthepud]

I think you are paying too much attention to small changes in the blood test results. You are OK as long as your TSH does not go very low (<0.3?). Even then it is OK you just pay more attention to any signs of overactivity. Just go with the dose you feel best on.

Targetting the upper parts of the fT3 and fT4 reference intervals is wrong. Many patients may need this but it is not where the general population is. I would target fT3 mid-interval, as an initial target and then tune your dose according to symptoms but keeping an eye on the blood test results.

[greygoose in reply to jimh111]

The general population isn't hypo.

[Judthepud in reply to greygoose]

I'm glad of your reply Greygoose. What's your advice in the circumstances??

[greygoose in reply to Judthepud]

I agree that the slight change is nothing to worry about, blood tests are just a guide. So often we see people thinking they're over-medicated, because of the symptoms, but when they get tested, they find they're under-medicated. So, tests are good for that, but not as cast iron, must-reach-this-level regulators, and not to agonise over. They aren't reliable enough for that, and everyone is different. I believe the point of thyroid hormone replacement is to increase slowly until your symptoms go away and don't come back.

[jimh111 in reply to greygoose]

I'm not too keen on setting targets for fT3, fT4 because it assumes you know the cause and the effects of the hypothyroidism. It might be OK to set an initial target, just to get you started and in this case it seems reasonable to restore the patient back to the levels they were at before they became hypothyroid. i.e. typical levels of the general population. This works for about 85% of patients diagnosed with primary hypothyroidism. The rest, which includes I suspect most patients on this forum, will need different levels. I wouldn't like to regard a target as anything other than an initial starting point to work up or down from.

[greygoose in reply to jimh111]

I don't think you should set targets, either. But neither do I think hypos should compare themselves to euthyroid people. That's what doctors do, and it doesn't work.

[Judthepud in reply to greygoose]

Thanks Greygoose. Do you think I should stick on my current dose, or should I edge up a wee bit to say 150mcg daily?